| 摘要 |
<p>A remote pressure-controlled three-way valve device (11) for use as a tire valve in a tire inflation control system in transport vehicles, without needing additional control lines. The device comprises a plunger (21) axially traversed by an inlet passage (17A) normally closed by an inlet valve urged by a spring (23). The outer side wall of the plunger has a recess (35) in which a o-ring (37) extends that, in addition to abutting against the steps (41) of the recess to limit the plunger stroke, keeps an outlet passage (15B) closed to a venting port (17B) formed in the side wall of the body (13) of the device. The plunger includes an o-ring (43) preventing short-circuits between the inlet passage and the vent port and a spring (47) for counteracting friction between the o-ring and the inner wall of the device. Filters (51A; 51C) are arranged in respective ports (17A, 17C) connectable to the input air-pressure supply and the tire inner tube and furthermore provide fixed seats for the springs to bear on. The plunger may dwell in a stable intermediate position that opens the outlet or deflation passage is controlled by sending an air pressure through the inlet port at 50% of the normal pressure. <IMAGE></p> |
